Means for drawing sheet-glass.



I. W. OOLBURN. MEANS FOR DRAWING SHEET EGLASS.

APPLICATION FILED FEB. 12, 11908.

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M H F. M H a i L 9 E X 8 s 1 a 0 N 7 W 9 W I. W. OGLBURN.

MEANS FOR DRAWING SHEET GLASS.

APPLIOATION FILED FEB. 12, 1908.

970,182. Patented Sept.13,1910. I

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a Fm); Fm m Witnesses v v K i i 1% I w I i @fi .MM' (71 i I 4! w I Attomey I. W. COLBURN.

MEANS FOR DRAWING SHEET GLASS.

ABPLIOATION FILED FEB. 12, 1908.

6 SHEETS-SHEET 3.

. Inventor 1 dnw By Attomeyd 11' W. OOLBURN. MEANS FOR DRAWING SHEET GLASS.

APPLICATION FILED FEB.12, 1908.

? 1 a Patented Sept. 13, 1910.

/ a SHEETS-SHEET 4.

Q R Q 1 Witnesses I. W. GOLBURN. MEANS FOR DRAWING SHEET GLASS.

APPLICATION FILED FEB. 12, 1908.

Patented Sept. 13,1910.

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mum's TDRNEYS I. COLBURN.

MEANS FOR DRAWING SHEET GLASS.

AP'ILIUATION FILED FEB. 12, 1908.

Patented Sept. 13, 1910.

BBHEETfl-BHEET 6.

BMENTOR dmg, ML,

$3? \3 ATTORNEYS %'W wi'rkzssas NEW JERSEY.

- To all whomit'may concern:

Be it known that I, IRVING W. COLBURN, of Franklin, Pennsylvania, have invented, a new and useful Improvement in Means for Drawing Sheet-Glass, which improvement is fully set forth in the following specification.

This invention relates to the art of drawing sheet glass from a mass of molten glass,

and more particularly to a combination of mechanism designed to perform the drawing operation. It is well known in this art that when attempts are made, to draw glass in sheet form from a mass of molten glass, there is a tendency on the part of the sheet being drawn to narrow or pull to a string or thread, and in a certain application for Letters-Patent of the United States for improvements in continuous sheet-glass drawing means, Serial No. 368,096, filed April 13th, 1907, I have shown a machine for drawin sheetlass in which there is com- & b

" bined with the drawing mechanisn't means for overcoming the narrowingtendency of the sheet and acting to maintam the drawn sheet of substantially unlform wldth. In

certain Letters-Patent issued to myself solely and also in U. S. I atent 861,948, issued Oct. 15, 1907, to myself and Edgar lVashburn as joint inventors, there are also shown means for drawing a sheet of glass,

combined with megns for maintaining the width of the sheet substantially uniform throughout the drawing operation. The continuous sheet-glass drawing means described and illustrated in said patents and i a to a more or, less lateral stretching effect.

tainin The means for drawing the sheet of glass may be any suitable means for this purpose. The means chosen for illustration herein, is the glass-'drawing means shown in my application aforesa d, to wit, areceptacle conmolten glass with skimming or rib annihilating rolls revolving with their lower peripheries immersed in the mass of molten STATES PEN'I 'IRV-ING w. COLIBURLL'OF FRANKLIN, PENNSYLVANIA, Assronon T0 ooLBUxN'M'A- CHINE GLASS COMPANY, or FRANKLIN, PENNSYLVANIA, A

MEANS FOR DRAWING SHEET-GLASS.

. speed exceeding that of the upwa'r conroRA rIoN, or

glass, and a drawing chamber having a carrier and suitable gripbars for engaging the sheet and drawing it upward over a bending roll, whereby'the sheet is turned from ayertical to a horizontal position.

invention is not limited to such speci 10 form of drawing mechanism, since any suitable drawing mechanism would bewithin the scope of the present invention. The width-maintaining and sheet-stretch ing means of the present invention'consist of two sets or pairs of co-acting rolls, vwhich are located on opposite sides of the drawingm'echan sm proper and slightly above the one is a right-hand and the. other is a lefthand screw-thread, and as thesheet is being drawn, the edge portions'of the sheet. are seized between the screw-threaded rolls,

which rolls are revolved Wliil'l'l their inner or adjacent surfaces moving upward and outward. For convenience of operatiom-the rolls,are slightly tapering or conicalin form, though this is not essential.

rollsiare driven at a peripheral speed exceeding that of the upward or linear move ment of the sheet, they willnot act to mainlain the width of the shcet," nor will they have any stretching effect thereon. I haw. therefore provided driving means for said rolls capable of being so adjusted that the rolls will have imparted theretoa peripheral orlongitudinal movement of the sheet bein I drawn. By this means I am enabled not on y to entirely overcomethe narrowingfitendency of thesheet, but to slightly stretch the same e ncient form of drawing means, the resent Specification of Letters Patent. Patented-Sept. 13, 1910. 2 Application filed February 12, 1908. Serial No. 415,587.

IVhile such drawing means constitute an a5. v I have discovered that unless these screw-threaded during the drawing operation. In addition to the width-maintaining andstretching action which the rolls have uponythe sheet;- they also assist in drawing the sheet of' glass. It the rolls became heated to asuflicient'deg ree, the plastic glass would adhere thereto and thus defeat the very objectlof theiremployment. Theirl proximity to. the molten glass from which the sheet iscdrawn' and their contact with the hot-sheet-Wflnld' inevitably heat the rolls to the degree where the glass would stick to the rolls, and to avoid this the invention includes cooling means for the rolls. 7 v H The invention further consists in a pair of approximately positioned, horizontally -rotated, revoluble, cooperating. screw-threaded jjrolls, which act to stretch the sheet during the drawing operatiom'combined with means for drawing the sheet as a whole, and also.

with automatic means for h iting the extent of the stretching action exerted by the rolls upon the sheet. As herein shown, said limiting means consist of milled-or knurled surfaces on the rolls adjacent to the screwthreaded sections or portions of the rolls but exterior thereto. In another form, the means, for limiting the stretching action of the rolls upon the sheet consists of screw-threads upon the ,rolls, which screw-threads on each of illustrating the invention, I have shown in the accompanying drawings certain 'embodiments of the invention, which embodiments, however, are to be taken as illustrative only and not as designed to indicate the scopeof the invention, reference being. had to the claims herein for that purpose.

In the drawings Figure l is'a' top plan view of my width-maintaining and stretching means, together with the shafting, gearing, 'etcl, cooperating therewith to drive the same; Fig. 2 is a sldc elevation of Fig. 1, parts being broken away, and Fig. 3 is an end elevation of Fig. 1, with parts shown in section; Fig. {i is a broken sectional detail on a large scale of the drawing roll andfcon nected driving shaft; Figs..5, 6, 7, 8, 9 and l0' are top plan views of some of the forms which the inventive idea embodied in therollsmay assume; Fig. 11 is a vertical. section on the line XI -X.I, Fig. 12, showing the width-maintaining and stretching rolls in position on the machine and the driving mechanism for said rolls andfor thesheetdrawing devices; Fig. 12 is a central, vertical, longitudinal section. on the line 1511i XII, Fig. 11,-showing the forward or arming chamber end of my improved continuous sheet-drawing machine; Fig; 13 an enlarged brokentop plan view showing the width -maintaining and side-stretching rolls in position, and illustrating their action upon the sheet of during the drawing operation; and Fig. is is a'broken front elevation illustrating the action of the rolls uponthe sheet of glass.

Referring to the drawings, in which like reference numerals, indicate 1 like part. throughout the several views,;1, 2, indicate two rolls here shown slightly tapering of intenneshing spur gears 10 and 11. Each rigidly mounted upon the. base, while the bearing 6 is so mounted as'to be cap'ableof a horizontally rotative movement. Shaft 3 is adapted tobe revolved by means of. beveled gears 8 and 9, the gear 8 receiving driv- .5 ing motionthrough the shaft 8, in a man ner hereinafter described. Motion is transmitted through shaft 3*to. shaft 4 by means of the shafts 3 and 4 is rovided at its outer an. end portion with a stu ng box 12 through which passes the pipe 13, by means of which water or other cooling fluid is conducted to the interior of the rolls. The pipes 13 ter-- Ininate within therolls which are made hollow for that pur ose, and-the cooling fluid returns by way 0 the space between the exterior diameter ofv the ipe 13 and the interior of the hollow sha t 3 or 4, as the case may be, the outer ends of the pipes 13 bei connected to a suitable source of supplyyan the space between the pipes 13 and .the shafts 3, 4, being connected with a suitable discharge condu1t,'in a manner which will be well understood. Rigidly connected to the bearing 6 is an outwardly extending arm i 15 which is connected to a s ring connection 14 at one end, the other end of which attached to any suitably firm object, such as a structural detail 15 or a 'artof the wall of the furnace or working 0 amber.

The rolls 1, 2, are each screw-threaded at their free'ends, the roll 1 having a left-hand indicated by the arrow 0, Fig. 1'. As before "1', 2, has thereon adjacenttothe screwthreaded portions'l,

screw-thread 1 and the roll 2a right-hand thread 2, so that when said terminals revolve in the direction indicated bythe arrows a, b, Fig. 1, respectively, the'lead-or travel of said threads 1s awayfrom the free e ends of the rolls, that is, inthe direction stated, the revolving motion impartedto said rolls is such that their peripheral speed is greater than the speed of the upward or linear travel ofthe sheet of glass 16 (see .Figs. 12 and let), the edges ofwhich are being acted upon 10 said rolls. The result of this relative di .erdntial speed of-travel will be hereinafter more fully explained. Still referring to Fig. 1, .eahh'bf; the rolls 2, a milled orknurled portion 1", 2".

Referring to Fig. 12, thedrawi ratusherc shown is substantially" scribed in detail in my aforesaid tion, and consists,generally 'speakin endless carrier 30 cooperating "with bars 31, carriedon elidless' chalins32ft carrier 30 and the chains 32Emeving in? direction indicated by the arrowdaniqf i parts being so positioned that the grip bars 31' act to grip the sheet 16 between said bars and the endless carrier 30. The sheetmay be started in any suitable way, as by the introduction of a bait 33, in the manner fully set forth in my aforesaid application.

The sheet is drawn from a mass of molten,

glass lying between two skimming or ribannihilating rolls 26,- upward between a pair of shields 27 and over a bending roll 24, suitable means in the form of burners 25, 25, being employed to regulate the temperature of the glass during the drawing operation.

My improved width-holding device is applied to and combined with the above-de--.

tioned as toadapt them to cooperatively engage the edge portion of the sheet of glass. Said rolls are preferably positioned at a right angle or perpendicular to the travel of the sheet of glass. Motion is communicated to the shaft 8 and the holding device through shafts 8", one on each side of themachine (Fig. 11), which shafts 8" are independently driven \through separate individual variable speed pulleys 19, 19, motion being in turn transmitted tosaidpulleys from jack-slniit-QO, from which shaft 20 motion is also transmitted to the drawing mechanism proper through shaft 21. Jack shaft 20 is operated by means of the variable speed pulley 22 which receives motion from any suitable.

source of power, hereshown as an electric motor 23.

vIt will be readily understood that by the above arrangement of power transmission, .the speed of the machine as a whole may be varied at"pulley22 and the speed of the width-holding devices may be individually varied each by means of its pulley 19, and

' thus the lmrmonious action of the drawing and the \vhltlr-lrolding elements is duly pro vided for.

The operation is as follows: The operation of drawing the sheet is started in the usual or any suitable manner, as by means of the bait 33, which is inserted into the molten glass, then drawn upward and passed over the bending roll 24, after the manner 'set forth in my aforesaid application. If 'the bait is .not sufficiently long totstart a sheet of glass wide enough for its edges to be received between the two setsof rolls 1, 2, onthe opposite sides of the machine, the edges "of the newly formed sheet are seized by nieans of hand-hooks and stretched laterally until it is suflicjieiitly wide to be enga ed at both edges by the screw-threaded rol s. For the purpose 'ofso' receiving the edge portions of the sheet; the" terminal 2 is moved outwardly or away from terminal- 1 by turning its shaft 4 upon the bearing 6,' against the tension of the spring connection 1%,and after the edge of the sheet of'glass is introduced between the rolls, the terminal 2 is permitted to again approach terminal 1, and the spring connection 14: acts to yield-.

Ingly hold said terminal 2 in working position. When the edges of the outwardly moving sheet of glass are thus positively received between the rolls, the peripheral speed of said rolls is so regulate by means of the variable speed pulleys 19 thatthe said peripheral speed shall exceed the speed with which the sheet of glass is traveling upward, and by reason of this differential rate of speed the action of the threads 1, 2, upon the surface of the sheet of glass tends to draw saidedges farther outward,'that is, p v

farther and farther between the rolls in. the

direction indicated by the arrow 0, Fig. 1,

and thereby a lateral stretching action is continually exerted'uponthe sheet. This action would cause the edge of the sheet of glass to be carried fartheran'd farther between the holding rolls if'no provision were made to prevent it, provided the rolls were 'over-speeded, that is, provided that they glass passes in between said milled sections,

the rolls 1, 2, are thrown suflicien tly apart so that the action of the screw-thread "is greatly or wholly reduced (see Fig. .17), and the natural tendency of the glass to narrow down is asserted, and the edge of the glass recedes to a position between the threads 1', 2. It will be seen, therefore, that during the drawing operation the immediate edge of thesheet of glass is repeatedly entering between and receding from said milled sections, and this give. to the edge of the sheet the appearance shown in Figs. 11 and 14, which is somewhat exaggerated for the purpose of clear illustration.

From the above description, it will be readily understood that the action of the rolls'l, 2, aside from overcoming the narrowing tendency of the sheet, would be such as to have a stretching action upon theisheet, and also to materially assist the drawing mechanism in causing the upwardor'drawingmovementof the sheet of glass.

An examination of the sheet of glassdrawn with the aid of this improved width "hold ng and stretching device discloses a i v ing threads T, T, which threads l3, wherein will be noted that the edge portion is comparatively thick throughout f the area Whereit -is acted upon by the thread ed rol1;'that said thicknessv is considerably reduced just inside of said area; and beyond such reduced area the sheet assumes a normal. thickness which is maintained substantially uniformthroughout the body of the sheet.

Belowthe rolls 1, 2,,the edge of the forming sheet assumes the line A (see Fig. 14),

which clearly exhibits the characteristic tendency of the sheet to. narrow down when pulled intosheet form, and also discloses the stretching or lateral pulling action of the rolls 1, 2, thereon, whereby the width of the sheet is maintained.

.There are several modifying influences which combine to produce the precise sec tional form of sheet shown in Fig. 13, which influences are as follows: It will be readily understoodthat sheet 16 being, at the point where it is operated upon by rolls 1 and 2, in close proximity to themolten mass from which it is drawn, is injfa very pliable and plastic, condition, andparticularly susceptible to the influences of heat or to a rise. or .fall in-teniperature.

sheet from the action of said radiated heat, the water shields27, 27,,are interposed be-' tween the sheet and said rolls. Where sheet 16 isthus shielded and the temperature 1 thereb regulated, the thickness of the sheet I is uni ornL. There is, however, a small area of the sheet appro% mate"to each edge which is not thus shielde and is therefore subject to the direct action of said radiated heat,

' and yieldsmore readily than other portions of the sheet to the stretching action of the width-holding rolls 1, 2, and thus causes reduced area B approximate to either edge portion of the sheet. The action of the heat from burners 25 and the object of providing the same areclearl set forth in. Patent 836,439, before mentioned, as also the function of the skimming or rib annihil'ating rolls 26 and the shields 27, and hence need not be more specifically recited hereinj In the forms of rolls shown in Figs. 6', 7, 8, 9 and 10, the rolls of Figs. 6, 7. and 9 differ only in the form or pitch of the hold ing or; stretching threads; In Figs. 8 and 10, instead of. the milled or knurled surface or arrestave an opposite lead or travelfrom the holding thread on the same roll.-

1; 2 there' are shown releasing "With the milled er knurled form or roll such as shown in Figs. 5, 6, 7 and 9, the discontinuance of the stretching actionof the rolls upon the sheet due'largely to) the narrowing tendency of the sheet whichis constantly present during the drawing operation, and to the slight opening or spreading of the rolls apart when the thicker edge of the sheet passes between theknurled portions. With the rolls shown in Figs. 8 and 10, however, having threads T, T, of reverse lead; the said reverse threads act positively to throw the edge of the sheet inward.

stantly being thrown outward toward the reverse threads T, T, and by them constantly thrown inward toward the threads 1, 2'.

It will be readily understood by those skilled in the art that various changes. in

form and the proportion "and relation of parts may be made without departing from the spiritof my invention, and all "such changes are designed to be covered and ineluded by my claim'sherein'.

"What is claimed 1s: V

. With this form of rolls, the sheet is con-* 1. In sheet-glass drawingapparatus, the

.combination of sheet-drawing me'chams'm,j

with width-maintaining and sheet-stretching means, and. devices limiting the stretching action of said means.

2. In sheetlass drawin ap aratus, they a g P combination of sheet-drawing mechanism, '95 threaded rolls, the-rolls of each set having 1 with two sets of revolubly mounted screwthe one a right and the other auleft'screw-j.

thread, and means imparting a peripheral speed to saidrolls in excess of the lineal. speed imparted to the sheet of glass by the drawing mechanism.

3 In sheet-glass drawing apparatus, the I combination of sheet-drawing mechanism,.

with two sets ofjuxtaposed, horizontally re lated, oppositely-screw-thrkaaded I revoluble' rolls, meansyieldably holding the-ltwon'rolls of each set in juxtaposition, means driving. i

said drawing mechanism andsaid rolls, and means varying-v the speed ofsaid rolls indemechanism.

pendent of the speed 'of'said drawing 4. In sheet-glass drawingapparatus, thecombination of sheet-drawingmechanism,

with a plurality of sets of width-maintain ing devices engaging the opposite edge por-' 1 tions of the sheet, each of saidsets comprising two cooperating screw-threaded rolls,

and means driving said rolls'at a peripheral speed exceeding the-lineal speed of said drawing mechanism. 5. In sheet-glass drawing apparatus, the

combination of sheet-drawing .m'echanism,

with-a plurality of sets of ,widthsmaintain l 6 ingdevices engaging the opposite edge portions of the sheet, each offsaid sets comprisdriving said rollsflat a peripheral speed exceeding the line mechanism.

6. In sheet-glass drawingapparatus,

31 Speed of said drawing 'ing a pair of coiiperating rolls, and means combination of sheet-drawing mechanism, of sets of sheet-stretching the opposite edge-portions means limiting the stretchwith a plurality devices engaging of the sheet,"'and ing action of said devices.

with sheet-stretching 7: In sheet-glass drawing apparatus, the combination of sheet-drawing mechanism, with width-maintaining means at each edge of the sheet acting in opposition to the nar- 10 rowing tendency of the sheet, and devices intermittently relieving the sheet from the action of said means.

8. In sheet-glass drawing apparatus, the combination of sheet-drawing mechanism, means acting to broaden the sheet during the drawing op- .eration, and devices acting to positively vlimit said broadeniijg of the sheet within .rpredetermined linesf 9. In sheet-glass drawing apparatus, the

-' combination of sheet-drawing mechanism.

with width-maintaining sheet-stretching drawing rolls acting on the edge portions of the sheet during the drawing operation, 5 and means mparting a peripheral speed to 55 lineal speed of so each edge portion of the said rolls exceeding the lineal speed of said drawing mechanis v 10. In sheet-glass drawing apparatus, the mbination of sheet-drawing mechanism, ith Width-maintaining sl'ieet stretching screw-threaded drawing tells acting on the @dge portionsfof the sheet during the drawfing operation, and means unpart1ng a --peripheral speed 110 Stud rolls exceeding the said drawing mechanism. 11.- In sheet-glass drawing apparatus, the combination of sheet-drawing mechanism, with two sets of juxtaposed screw-threaded revoluble rolls one set yieldingly engaging sheet of glass, variable-speed driving devices oporably con- I married to said drawing mechanism, driving means connected to each set of rolls, and devices varying the speed of said rolls h de pendently of each other an f he drawing mechanism.

p0 of rolls engaging the respecti 12. In sheet-glass drawihg apparatus, the comhii'iation of means drawing a sheet of glass fronrla t'nolten supply, with two pairs ve edge portions of the sheet, means upon said rolls etfecting a lateral stretching of the sheet, and.

means automatically limiting said stretchins; action. V

18; In sheet-glass drawing apparatus, the combination of means drawing a sheet of glass from a molten supply, with two pairs of rolls engaging the respectlve edge portions of the sheet, means uponsaid rolls 50 effecting a lateral stretching of the sheet,

and means upon 'iimiting said stretching action.

' 14. In sheet-glass dravv'ing apparatus, the pombination of means drawing a sheet 01 said rolls automatically said rolls exceeds of said sheet, and automatically limiting said stretching the peripheral speed of the lin al speed of travel means action.

16. In sheet-glass drawing apparatus, the combination of ineans drawing a sheet of glassfroin a molten supply, with two pairs of rolls, one pair engagingbeach edge portion of the sheet, means on said rolls effecting the lateral stretching of the sheet when the peripheral speed of said lineal speed of travel of said sheet, and means on said rolls automatically limiting said stretching action.

17. In sheet-glass drawing apparatus, the combination of a receptacle containing a mass of molten glass, sheet-drawing mechanism drawing a sheet of glass from said molten mass, means applying heat to the surface of said molten mass during the drawing operation, means shielding the central portion or main body of the sheet from the direct action of said heat, and a pair of screw-tln'eaded rolls engaging the two edge portions of the sheet, one rollof each pair roll having left screw-threads. 18. In sheet-glass drawing apparatus, the combination of a receptacle containing a mass of molten glass, sheet-drawing mech-' anism drawing a sheet of glass from said inass, means applying heat to the surface of said molten mass during the drawing operation, a pair of skinuning rolls with their peripheries immersed in'the surface of the molten mass,'ono on each side of the sheet, means shielding the central portion or main body of the sheet said heat, a. pair of screw-threaded rolls engaging the two edge portions of the sheet, one roll of each pair having right screW- threiuls and the other roll having left screwthrcads, means cooling said rolls, and means drivingsaid rolls at a peripheral speed exceeding that of the longitudinal speed of the drawing mechanism.

19. In sheet-glass drawing apparatus, the combination of sheet-drawing mechanism, with. two pairs of right and left screwthreaded rolls, one engaging each edge portion of the sheet during the drawing oper- 1 ation, means nnpartmg a peripheral speed supply, with two pairsrolls exceeds the ing the lateral stretching of the sheet when having right screw-threads and the other from the direct action of to said rolls in excess of the longitudinal speed of the drawing mechanism, and coolingnieans for said rolls. v e

' 20. In sheet-glass drawlng'apparatus, the

c0 mbination of sheet drawing mechanism.

.W th :two' pans of rightl and leit i serewe l threaded rolls, one engaging each edge pontion of the sheet during the drawing operation, means imparting a peripheral speed of said rolls in excess of the longitudinal speed of said drawing'mechanism whereby ing Witnesses.

the sheet is stretched as drawn, means on said rolls limiting said stretching action, and I coolnig means for send rolls.

In: testimony Whereofi I have signed this-15 specificatiqn in the presence of two subscrib- IR ING W. jooL U n' Witnesses: i Q i Bnss LOUISE BLACK, WM. B. GRIFFEN. 

